Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: specialk13 on November 21, 2019, 10:43:11 am
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Hello, this is my first post and hopefully, one of many if I get this project going :)
My question is, how difficult is it to do the hand wired conversion on a Pro Junior? Is it more difficult than say a 5E3 kit build? I have performed some modifications to amps in the past and have a lot of soldering experience but this would be my first PTP board.
I don't need to be persuaded not to do this but I also don't want to go ahead with it if it's considered a difficult project for someone with my skill set. I also have the perfect donor amp, which is why I'm entertaining the idea instead of going with a new kit.
Thank you!
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it's pretty easy if you put 90% into planning and 10% into building, most of us start the other way around :icon_biggrin:
by PtP, no turret/eyelet just lugs?
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Thank you for the reply, I haven't decided 100% but I will probably go with a turret board now that you mention it.
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Will you be following Hoffman's plans (or another proven plan) for a Pro Jr. conversion? If so, it should be pretty easy. If not, can you read a schematic and draw a layout based on that schematic?
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I would be following the Hoffman plan as I think it has the most complete information.
Will you be following Hoffman's plans (or another proven plan) for a Pro Jr. conversion? If so, it should be pretty easy. If not, can you read a schematic and draw a layout based on that schematic?
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Does anyone have any recommendations on what I can modify to make the amp sound more like a Vox/British amp? That's the direction I would like to go with this one.
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I highly recommend this...
http://sluckeyamps.com/Dual_Lite_(British).pdf
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Hmm that's quite a divergence from the pro jr layout. I was hoping I could adjust some values, etc. to the Hoffman layout to get there.
I highly recommend this...
http://sluckeyamps.com/Dual_Lite_(British).pdf
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Hmm that's quite a divergence from the pro jr layout. I was hoping I could adjust some values, etc. to the Hoffman layout to get there.
I highly recommend this...
http://sluckeyamps.com/Dual_Lite_(British).pdf
Gonna be more involved than just adjusting a value, etc. You could keep most of the Hoffman stuff and just replace his V1 circuit with one of the British preamps shown in my dual lite. I would also convert his fixed bias circuit to the simpler cathode bias circuit.
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Understood, I'll give that another look. Thanks!
Hmm that's quite a divergence from the pro jr layout. I was hoping I could adjust some values, etc. to the Hoffman layout to get there.
I highly recommend this...
http://sluckeyamps.com/Dual_Lite_(British).pdf
Gonna be more involved than just adjusting a value, etc. You could keep most of the Hoffman stuff and just replace his V1 circuit with one of the British preamps shown in my dual lite. I would also convert his fixed bias circuit to the simpler cathode bias circuit.
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I just took a look at Hoffman's conversion page. That's gonna be a fairly challenging project. I'm gonna back off my suggestions and instead advise you to do the conversion exactly as Hoffman shows. Then once you have a working amp we can talk about mods.
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I also have the perfect donor amp,
I missed this statement. Your perfect donor is a Pro Junior, right?
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Correct, version IV pro junior.
I also have the perfect donor amp,
I missed this statement. Your perfect donor is a Pro Junior, right?